1. Field of the Invention
The present invention relates to an optical disk recording apparatus for recording a signal onto a disk using a laser from an optical pick-up, and reproducing a signal recorded on the disk using a laser.
2. Description of the Related Art
Disk players capable of signal reading from a disk using an optical pick-up are popular. In particular, optical disk recording and reproduction apparatuses capable of, in addition to signal reproduction, signal recording onto a disk using a laser emitted from an optical pick-up have recently been introduced into the consumer market. Moreover, optical disk recording and reproduction apparatus capable of signal recording onto a disk under rotation control at a high constant linear velocity (CLV) twice, four, six, eight, ten, or even twelve times a standard linear velocity, have been developed.
Optical disk recording and reproduction apparatuses are constructed adapted to signal recording in response to a record command from a host computer. Specifically, in a recording operation, signals to be recorded onto a disk, or recording signals, are temporarily stored in a buffer RAM, and read therefrom to be recorded onto the disk.
In a normal signal recording operation, signal writing from a computer device into a buffer RAM, signal reading from the buffer RAM, and signal recording onto a disk are all carried out in accordance with the amount of recording signal data and signal recording condition. When the signal writing speed at which to write signals onto the buffer RAM becomes slower compared with the signal recording speed at which they are recorded onto a disk under the above described signal recording condition, recording signals in the buffer RAM may run short, leading to suspension or discontinuation of signal recording onto the disk. This phenomenon, generally referred to as buffer under-run, is more likely to occur when higher disk rotation speeds are employed in signal recording onto a disk.
In order to address this problem, techniques are suggested including one in which signal recording onto the disk is suspended when buffer under-run occurs, although signals are continuously written into the buffer RAM during the suspension, and the suspended signal recording is resumed when a predetermined amount of signal data has been stored in the buffer RAM.
Resumption of once suspended signal recording may comprise setting a signal recording resumption point at a point at which the signal recording was suspended, and controlling the signal recording such that a signal after the resumption is recorded onto the disk so as to continue from the signal recorded onto the disk just before the suspension.
As described above, conventionally, signal recording onto a disk is suspended when the amount of signal data stored in the buffer RAM has been reduced below a predetermined amount, and resumed when it has been increased to a predetermine amount. This, however, has a problem such that, when the optical disk recording and reproduction apparatus completes signal recording as instructed by a host device, the host device has no means of ascertaining whether or not the signal recording just completed has ever been suspended and resumed during the process.
The present invention has been conceived to overcome the above problem and aims to provide an optical disk recording apparatus capable of solving this problem.
According to a first aspect of the present invention, there is provided an optical disk recording apparatus, comprising a control circuit for controlling data recording onto a disk so as to suspend upon detection of data shortage in a buffer memory, and resume upon detection of the fact that a sufficient amount of data has been stored in the buffer memory; and a counter for counting the number of occurrences of suspension of data recording onto the disk (which is basically equal to that of resumption of data recording onto the disk) as a result of control by the control circuit.
According to a second aspect of the present invention, the optical disk recording apparatus may have an output section for notifying an external computer device of the fact that signal recording onto the disk is suspended and resumed under control of the control circuit.
According to a third aspect of the present invention, the optical disk recording apparatus may comprise a location circuit for locating a point on the disk at which the signal recording was suspended and resumed under control of the control circuit.